adv. Southern & Midland US
[Alteration of that way.]
Our Living Language The history of the English language is full of examples of epenthesis, the addition to a word of a vowel or consonant not part of the original word. This process is still active in regional dialects. Two examples now used chiefly in Southern and Midland dialects are thisaway and thataway, which show epenthetic vowels intruding between this way and that way. Another highly excoriated instance of vowel epenthesis, not regional, is the pronunciation of athlete as (ăth′ə-lēt′).
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
jocular dialect US in that direction: He went thataway..
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014